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1.
We consider aspects of the interaction between a V-type three-level quantum system and the bichromatic field of two waves,
one of which is assumed to be weak. We trace the dynamics of splitting into individual components for the spectral contours
of the absorption coefficient (gain) for the signal wave. We discuss the effect of amplification of the signal wave for its
frequency-degenerate two-wave interaction with pumping, when the field frequency is tuned to the “zero dispersion” point.
We determine the conditions with respect to the concentration of resonant atoms and the spectral regions of the frequencies
of the interacting waves for which, in order to correctly describe the effects under consideration, we need to take into account
the effect of pumping and the signal in both dipole-allowed transitions of an ensemble of V type three-level quantum systems.
We present the results of numerical calculations of the imaginary and real parts of the susceptibility of the resonant medium
at the frequency of the signal wave, as a function of the parameters for the high-power radiation and resonant transitions
of the quantum V system.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 631–636, September–October, 2007. 相似文献
2.
A theory of interaction of a three-level V-type quantum system with a bichromatic field of two waves, one of which is weak, has been developed. It is suggested that the upper two levels of this system are closely spaced and, therefore, both waves interact simultaneously with both allowed transitions. An expression for nonlinear macroscopic polarization of the V-system has been obtained by the density-matrix method.__________Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 1, pp. 67–71, January–February, 2005. 相似文献
3.
We consider the resonant interaction between atoms with hyperfine energy levels and a bichromatic radio-frequency field. Nuclear
Zeeman levels of an impurity center in a magnetic host form a structure of this kind. Using the spin-density-matrix formalism,
we solve the problem of coherent repopulation of a system of three of these levels under the action of a bichromatic resonant
radio-frequency wave, taking into account transverse relaxation, and note the connection between this effect and the well-known
phenomenon of coherent population capture when a laser bichromatic field interacts resonantly with a three-level system. We
discuss various possibilities for observation of this effect experimentally.
Zh. éksp. Teor. Fiz. 111, 1236–1244 (April 1997) 相似文献
4.
5.
Enhanced Kerr nonlinearity in a left-handed three-level atomic system driven by a bichromatic field
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Enhanced Kerr nonlinearity in a left-handed atomic system consisting of three levels driven by a bichromatic field is presented in this paper.Based on bichromatic field coherence,the real parts of the permittivity and permeability can obtain negative values simultaneously in the same detuning frequency region.By adjusting the frequency difference and the Rabi frequencies of the bichromatic field,the multi-band left-handed behavior of the presented atomic metamaterial is exhibited.Meanwhile,the enhanced Kerr nonlinearity can be realized in this multi-band left-handed three-level atomic system.It is shown that the third-order susceptibility possesses focusing or defocusing properties in the same frequency band. 相似文献
6.
In a semiconductor quantum dot, the IIx and IIy transitions to the polarization eigenstates, |x> and |y>, naturally form a three-level V-type system. Using low-temperature polarized photoluminescence spectroscopy, we have investigated the exciton dynamics arising under strong laser excitation. We also explicitly solved the density matrix equations for comparison with the experimental data. The polarization of the exciting field controls the coupling between the otherwise orthogonal states. In particular, when the system is initialized into \Y>, a polarization-tailored pulse can swap the population into |x>, and vice versa, effectively operating on the exciton spin. 相似文献
7.
Qiong-Yi He Xiao-Gang Wei Jin-Hui Wu Bing Zhang Jin-Yue Gao 《Optics Communications》2008,281(11):3137-3142
In a Doppler-broadened three-level Λ-type system driven simultaneously by a coupling laser and two equal-amplitude saturating laser fields with a frequency difference 2δ, the absorption spectrum of a weak probe laser exhibits multiple deep spectral holes through coherent hole-burning CHB with controllable numbers, widths, depths, and positions. More significant, changing δ or lasers directions, CHBs can degenerate into narrower and deeper spectral holes where the slope of the refractive index is very steep. The multiple narrow spectral holes in a single absorption profile are expected to have potential applications in high density storage, optical information processes, and slow-light. 相似文献
8.
Constantine Mavroyannis 《Molecular physics》2013,111(4):847-862
We have studied the stimulated Raman spectra arising from the interaction of a three-level atom with two strong electromagnetic fields whose initially populated modes ω a and ω b are in resonance with the two atomic transition frequencies. The Green's function formalism has been used in the limit of high photon densities to calculate the excitation spectra near the frequencies ω = ± ω ab = ± (ω a - ω b ). Expressions are derived for the relative intensities, which describe, apart from the usual Raman peak at the frequency ω = ω ab , four pairs of lorentzian lines peaked at the frequencies ω - ω ab = ± Ω a /√2, ± Ω b /√2, ± Ω and ± 2Ω, respectively, and having spectra widths of the order of 3γ0/4. The parameter Ω is defined as Ω2 = (Ω a 2 + Ω b 2)/2, where Ω a and Ω b are the Rabi frequencies of the two laser fields and γ0 is the spontaneous emission probability. Numerical calculations for selected values of the Rabi frequencies are graphically presented and discussed. Conditions have been established for which Raman gain processes are anticipated to take place. 相似文献
9.
Zheng Y 《Physical review letters》2008,101(4):049701; author reply 049702
10.
On the basis of the accurate solution of the Dirac equation for an electron in the field of a bichromatic plane wave consisting of two monochromatic waves propagating in the same direction, the probability of formation of an e+e– pair by a quantum in the wave field is calculated. The cases of small and large intensities of the wave components are considered, together with the transition in the limit to a constant field.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 46–53, February, 1977.The authors thank A. A. Sokolov for his constant interest in the work and discussion of the results. 相似文献
11.
This paper theoretically investigates the coherent phase control in
electron--argon scattering assisted by a bichromatic laser field.
The laser field is composed of a fundamental component and its
second harmonic. The incoming and out going states of electron are
described by the Volkov wave functions, and the electron--target
interaction is treated as a screening potential. Numerical results
for differential cross section of multiphoton processes vs the
phase difference between the two components of laser field are
discussed
for several scattering angles and
impact energies. 相似文献
12.
C. Mavroyannis 《Applied physics. B, Lasers and optics》2003,76(8):839-850
We have calculated the spectral functions for a number of induced excitations near the sum-frequency generation of a bichromatic field interacting with a three-level atom in the cascade configuration. Although the two-photon spontaneous emission is electric dipole forbidden, there are induced peaks whose subnatural line widths and spectral heights depend on the intensities of the bichromatic field. At low intensities of both laser fields, the maximum heights of the induced peaks take positive, zero, and negative values, indicating that the physical processes of absorption (attenuation), dark resonance (nonabsorbing state), and stimulated emission (amplification) are likely to occur at the sum-frequency generation of the two laser fields, respectively. The derived results are graphically presented and discussed. PACS 32.80.-t; 42.50.Hz 相似文献
13.
We study the effect of electron drag in a semiconductor superlattice during intraband absorption of a biharmonic electromagnetic wave in a process accompanied by the emission (absorption) of a phonon. The problem has been solved in the second order of perturbation theory. The effective interaction Hamiltonian method makes it possible to take into account the multiphoton nature of the electromagnetic wave absorption. With increasing field, the current increases and attains a peak value, after which it decreases in an oscillatory manner due to the ionization stabilization effect. 相似文献
14.
We analyze the solutions of the Klein–Gordon and Dirac equations describing a charged particle in an electromagnetic plane wave combined with a magnetic field parallel to the direction of propagation of the wave. It is shown that the Klein–Gordon equation admits coherent states as solutions, while the corresponding solutions of the Dirac equation are superpositions of coherent and displaced-number states. Particular attention is paid to the resonant case in which the motion of the particle is unbounded. 相似文献
15.
H.-K. Zhao J. Wang 《The European Physical Journal B - Condensed Matter and Complex Systems》1999,9(3):513-524
The time-dependent transport through an ultrasmall quantum dot coupling to two electron reservoirs is investigated. The quantum
dot is perturbed by a quantum microwave field (QMF) through gate. The tunneling current formulae are obtained by taking expectation
values over coherent state (CS), and SU(1,1) CS. We derive the transport formulae at low temperature by employing the nonequilibrium
Green function technique. The currents exhibit coherent behaviors which are strongly associated with the applied QMF. The
time-dependent currents appear compound effects of resonant tunneling and time-oscillating evolution. The time-averaged current
and differential conductance are calculated, which manifest photon-assisted behaviors. Numerical calculations reveal the similar
properties as those in classical microwave field (CMF) perturbed system for the situations concerning CS and squeezed vacuum
SU(1,1) CS. But for other squeezed SU(1,1) CS, the tunneling behavior is quite different from the system perturbed by a single
CMF through gate. Due to the quantum signal perturbation, the measurable quantities fluctuate fiercely.
Received 28 May 1998 相似文献
16.
研究了脉冲激发下单个半导体量子点中单光子发射的统计特性.在旋转波近似条件下,由系统粒子数演化主方程并结合量子回归理论推导了二阶相关函数的运动方程,利用此方程讨论了二阶相关函数随输入脉冲面积的关系.在窄脉冲宽度的脉冲激发下,单光子的发射概率p和效率η都随着强度的增强而产生振荡.研究表明,采用窄脉冲宽度,当输入脉冲面积在π附近时可以得到较高的单光子发射效率.
关键词:
半导体量子点
单光子发射
三能级系统 相似文献
17.
The quantum-mechanical theory of resonance fluorescence in a radio frequency (RF) field is developed for a system of two mixed nuclear levels. The case when the resonant γ ray absorption is permitted only for a single level is considered. It is shown that the bare energies of nuclear states vary simultaneously with the parameters of the mixing RF field, and an additional quasilevel appears in the system. The time-dependent probabilities of the corresponding transitions are calculated. 相似文献
18.
Borisov A. V. Goryaga O. G. Zhukovskii V. Ch. Sokolov A. A. 《Russian Physics Journal》1978,21(9):1136-1142
The exact solution of the Dirac equation for an electron in the field of a bichromatic plane electromagnetic wave — with components that are monochromatic waves propagating in one direction — is used to calculate the probability of e+e– pair production on a nucleus in the field of such a wave. This influence of the nucleus is treated perturbatively as an external Coulomb field. The cases of small and large values of the intensity parameters of the wave components are considered and the passage to the limit of a crossed field is discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 33–40, September, 1978.We are very grateful to V. R. Khalilov for a fruitful discussion of the results. 相似文献
19.
We have observed coherent oscillations in a multilevel quantum system, formed by a current-biased dc SQUID. These oscillations have been induced by applying resonant microwave pulses of flux. Quantum measurement is performed by a nanosecond flux pulse that projects the final state onto one of two different voltage states of the dc SQUID, which can be read out. The number of quantum states involved in the coherent oscillations increases with increasing microwave power. The dependence of the oscillation frequency on microwave power deviates strongly from the linear regime expected for a two-level system and can be very well explained by a theoretical model taking into account the anharmonicity of the multilevel system. 相似文献
20.
A. P. Saiko G. G. Fedoruk S. A. Markevich 《Journal of Experimental and Theoretical Physics》2007,105(5):893-899
EPR transient nutation spectroscopy is used to measure the effective field (Rabi frequency) for multiphoton transitions in a two-level spin system bichromatically driven by a transverse microwave (MW) field and a longitudinal radio-frequency (RF) field. The behavior of the effective field amplitude is examined in the case of a relatively strong MW field, when the derivation of the effective Hamiltonian cannot be reduced to first-order perturbation theory in ω1/ωrf(ω1 is the microwave Rabi frequency, ωrf is the RF frequency). Experimental results are consistently interpreted by taking into account the contributions of second and third order in ω1/ωrf evaluated by Krylov-Bogolyubov-Mitropolsky averaging. In the case of inhomogeneously broadened EPR line, the third-order correction modifies the nutation frequency, while the second-order correction gives rise to a change in the nutation amplitude due to a Bloch-Siegert shift. 相似文献